title: Vitamin D insufficiency and deficiency with stages of chronic kidney disease in an Asian population.
abstract: BACKGROUND
  Vitamin D insufficiency is associated with proteinuria and could be a risk factor for end-stage renal disease (ESRD). However, few studies have examined the significance of vitamin D insufficiency as a contributing factor for the development of ESRD in the Asian chronic kidney disease (CKD) population.
  
  
  METHODS
  Authors examined the relationship between vitamin D status and the staging of CKD using data from an outpatient clinic-based screening in 2,895 Thai CKD patients. Serum levels of 25-hydroxyvitamin D were analyzed according to CKD stages. Vitamin D deficiency and insufficiency were defined as a serum 25-hydroxyvitamin D concentration < 10 ng/mL and 10-30 ng/mL, respectively.
  
  
  RESULTS
  The mean (SD) 25-hydroxyvitamin D levels were significantly lower according to severity of renal impairment (CKD stage 3a: 27.84 ± 14.03 ng/mL, CKD stage 3b: 25.86 ± 11.14 ng/mL, CKD stage 4: 24.09 ± 11.65 and CKD stage 5: 20.82 ± 9.86 ng/mL, p<0.001). The prevalence of vitamin D deficiency/insufficiency was from CKD stage 3a, 3b, 4 to 5, 66.6%, 70.9%, 74.6%, and 84.7% (p<0.001). The odds ratio (95% CI) of vitamin D insufficiency/deficiency (serum 25-hydroxyvitamin D ≤ 30 ng/mL) and vitamin D deficiency (serum 25-hydroxyvitamin D < 10 ng/mL) for developing ESRD, after adjustment for age, gender, hemoglobin, serum albumin, calcium, phosphate and alkaline phosphatase were 2.19 (95% CI 1.07 to 4.48) and 16.76 (95% CI 4.89 to 57.49), respectively.
  
  
  CONCLUSIONS
  This study demonstrates that 25-hydroxyvitamin D insufficiency and deficiency are more common and associated with the level of kidney function in the Thai CKD population especially advanced stage of CKD.
authors.affiliation: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital, Bangkok, Thailand. satirapoj@yahoo.com.
authors.forename: Bancha
authors.initials: B
authors.lastname: Satirapoj
authors.forename: Pokkrong
authors.initials: P
authors.lastname: Limwannata
authors.forename: Amnart
authors.initials: A
authors.lastname: Chaiprasert
authors.forename: Ouppatham
authors.initials: O
authors.lastname: Supasyndh
authors.forename: Panbuppa
authors.initials: P
authors.lastname: Choovichian
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D015984:Causality; D015897:Comorbidity; D005260:Female; D006801:Humans; D007677:Kidney Function Tests / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D012307:Risk Factors; D013785:Thailand / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D